The dental implant is the closest thing in modern dentistry to a natural tooth. This is because an implant replaces more than the visible crown — it also replaces the root, thanks to a metal post imbedded in the bone.

But what if you have a metal allergy — are you out of luck replacing a tooth with an implant? Before answering this question, let's take a closer look at metal allergies.

An allergy is an overreaction of the body's immune system to a particular foreign substance. This response can be as inconsequential as a minor rash or as life-threatening as a shutdown of the body's organ systems. You can be allergic to anything, including metals.

Usually, these allergies are to specific kinds of metals. For example, about 17% of women and 3% of men are allergic to nickel, while smaller percentages are allergic to cobalt or chromium. Most allergic reactions to metal occur from external contact with jewelry or similar metal items that create rashes or other anomalies on the skin. On a more serious note, an allergy to metal in a body replacement part could result in the body rejecting it.

Metals have also played an important role in dental care, particularly dental amalgam used for tooth fillings. Dental amalgam is a mixture of a precious metal like gold or silver with other metals like copper, tin and, in small amounts, mercury. While dental amalgam has been used safely for decades, there have been rare cases of inflammation or rashes.

This brings us to dental implants and the most common metal used in them, titanium. The commercial version of this metal is highly prized in medical and dental applications because it has a special affinity with bone. Bone cells readily grow and adhere to the metal, which strengthens the bond between the implant and the jawbone.

Even if you have a rare allergy to certain metals, it's even rarer that would include titanium. In one particular study of 1,500 implant patients less than 1% reported any reaction at all.

If you're concerned, you can undergo testing to see if you react to titanium. More than likely, though, you'll be able to join the millions of other patients who have successfully restored their smiles with dental implants.